C REPL

crepl.sh

#!/bin/bash
# A REPL for C
# Mon Feb 11,  2019
# Aniruddha. A (aniruddha.a@gmail.com)

if [[ -z $(which gcc) ]]; then
    echo gcc not installed
    exit 1
fi
readonly FG_BLUE=""
readonly FG_RESET=""
readonly FG_GREEN=""
readonly FG_YELLOW=""
readonly FG_RED=""
readonly LPS1="${FG_BLUE}C> $FG_RESET"
readonly LPS2="${FG_YELLOW}C>> $FG_RESET"
readonly TMPB=$(mktemp --suffix='_creplbuf')
readonly TMPF=$(mktemp --suffix='_crepl.c')
readonly HIST=$(mktemp --suffix='_creplhist')

LPS=$LPS1

cleanup() {
    rm -f /tmp/{*_crepl.c,*_creplbuf,*_creplhist}
    exit 0
}

trap cleanup SIGINT SIGTERM  SIGHUP EXIT

create_tempf() {
    truncate -s 0 $TMPF
    for i in stdio stdlib stdarg stdbool stddef stdfix stdint string strings limits; do
        echo "#include<${i}.h>" >> $TMPF
    done
    echo "int main() {" >> $TMPF
    cat $TMPB >> $TMPF
    echo "return 0; }" >> $TMPF
}

dorun() {
    local EOUT=$(mktemp --suffix='_crepltmp')

    rm -f a.out
    create_tempf

    gcc $TMPF >& $EOUT
    if [[ $? -ne 0 ]]; then
        LPS=$LPS2
    else
        echo -en "$FG_RED"
        cat $EOUT | sed "s|$TMPF|<code>|"
        ./a.out
        rm -f a.out
        echo -en "$FG_RESET"
        LPS=$LPS1
    fi
    rm -f $EOUT
}

echo -e "Help:\n.clear - start afresh\n.quit  - end\n"
while [[ true ]]; do
    read -r LINE < <($(dirname $0)/rl -p "$LPS" -H $HIST \
        "for(i=0;i<n;i++){}" "while(){}" "return 0;" \
        int char float double \
        printf scanf strlen sizeof exit struct typedef void true false bool \
        .clear .exit .quit)
    if [[ $LINE =~ ^[.] ]]; then
        if [[ $LINE == '.clear' ]]; then
            truncate -s 0 $TMPB
        elif [[ $LINE == '.exit' ]] || [[ $LINE == '.quit' ]]; then
            rm -f $TMPB $TMPF
            echo Bye
            exit 0
        fi
    else
        echo -E "$LINE" >> $TMPB
        dorun
    fi
done

To use:
Compile the C program in the other gist (rl.c) as rl, and save it to the same directory as this script.